Add more bindings to OpenSSL, to be used by the Python _ssl module. (#2868)

* Add more bindings to OpenSSL, all are used by the Python _ssl module.

* Add a conditional: SSL_CTX_clear_options() does not exist before 0.9.8m

* 80 cols

* Condionally define the TLSEXT error codes.

* Address review comments

* Remove all parameter names
6 files changed